AS I walkd home about sunset, I saw in Fourteenth street a very young soldier, thinly clad, standing near the house I was about to enter. I stopt a moment in front of the door and calld him to me. I knew that an old Tennessee regiment, and also an Indiana regiment, were temporarily stopping in new barracks, near Fourteenth street. This boy I found belonged to the Tennessee regiment. But I could hardly believe he carried a musket. He was but 15 years old, yet had been twelve months a soldier, and had borne his part in several battles, even historic ones. I askd him if he did not suffer from the cold, and if he had no overcoat. No, he did not suffer from cold, and had no overcoat, but could draw one whenever he wishd. His father was dead, and his mother living in some part of East Tennessee; all the men were from that part of the country. The next forenoon I saw the Tennessee and Indiana regiments marching down the Avenue. My boy was with the former, stepping along with the rest. There were many other boys no older. I stood and watchd them as they trampd along with slow, strong, heavy, regular steps. There did not appear to be a man over 30 years of age, and a large proportion were from 15 to perhaps 22 or 23. They had all the look of veterans, worn, staind, impassive, and a certain unbent, lounging gait, carrying in addition to their regular arms and knapsacks, frequently a frying-pan, broom, &c. They were all of pleasant physiognomy; no refinement, nor blanchd with intellect, but as my eye pickd them, moving along, rank by rank, there did not seem to be a single repulsive, brutal or markedly stupid face among them.